Atomic Structure

Atomic Structure

Definition

• An atom is the smallest unit of a chemical element that retains the properties of that element.
• Atomic structure refers to the composition and arrangement of particles within an atom.

Subatomic Particles

• Protons:
  • Positively charged particles
  • Found in the nucleus (central part) of the atom
  • Number of protons determines the element (atomic number)
• Neutrons:
  • No charge (neutral)
  • Found in the nucleus along with protons
  • Number of neutrons determines the isotope of an element
• Electrons:
  • Negatively charged particles
  • Found in energy levels or shells around the nucleus
  • Number of electrons equals the number of protons (neutral atom)

Atomic Nucleus

• The central part of the atom containing protons and neutrons
• Positively charged due to protons
• Extremely dense and small compared to the atom as a whole

Electron Shells

• Energy levels or shells around the nucleus where electrons are found
• Each shell has a specific capacity for electrons
• Shells are designated by energy levels (1, 2, 3, etc.) or by letters (K, L, M, etc.)
• Electron shells are filled in a specific order (Aufbau principle)

Electron Configuration

• The arrangement of electrons in an atom's energy levels or shells
• Describes the number of electrons in each shell and the energy level they occupy
• Electron configuration determines an element's chemical properties

Atomic Structure

Definition

• Atom is the smallest unit of a chemical element that retains its properties
• Atomic structure refers to the composition and arrangement of particles within an atom

Subatomic Particles

Protons

• Positively charged particles
• Found in the nucleus of the atom
• Determines the element (atomic number)

Neutrons

• No charge (neutral)
• Found in the nucleus along with protons
• Determines the isotope of an element

Electrons

• Negatively charged particles
• Found in energy levels or shells around the nucleus
• Number of electrons equals the number of protons in a neutral atom

Atomic Nucleus

• Central part of the atom containing protons and neutrons
• Positively charged due to protons
• Extremely dense and small compared to the atom as a whole

Electron Shells

• Energy levels or shells around the nucleus where electrons are found
• Each shell has a specific capacity for electrons
• Shells are designated by energy levels (1, 2, 3, etc.) or by letters (K, L, M, etc.)
• Electron shells are filled in a specific order (Aufbau principle)

Electron Configuration

• Arrangement of electrons in an atom's energy levels or shells
• Describes the number of electrons in each shell and the energy level they occupy
• Electron configuration determines an element's chemical properties

Understand the composition and arrangement of particles within an atom, including protons, neutrons, and electrons.